[jaochoo]

Building an own HTPC from scratch, when do I need a separate graphics card and when can I just use onboard graphics? So far I understand that there are the following reasons:

1. Size. Obviously a mini-ITX case would not work for an additional card because it doesn't have enough space. While I really like these small cases, I also found a lot of nice micro- and macro-ATX cases. So this is not too important for me.

2. Gaming. I am actually not a big gamer. Actually I don't play games at all. But the reason could just be that I never bothered to buy a console and nice TV; computer was always a work machine. Still I enjoyed playing playstation, Xbox, wii, etc. when at friend's places. So the demand for playing games might come one I have a nice TV and HTPC. Still it would not be a top priority since I don't have much time anyways. But to what extent does gaming require a separate card? I like games like Pro Evolution Soccer, Mario Kart, Worms. Do these require an additional card?

3. CPU. I understand a separate graphics card will let the CPU focus on other tasks rather than handling graphics on top. But is this critical for a normal running XBMC? I dont plan to do much processing, converting, etc. on that machine but only want to have a smoothly running HTPC. Any other tasks (converting/ripping, downloading, etc.) would probably run on a media server (NAS).

4. 1080p/BluRay. To what extent is an additional card required to get the best HD video quality?

[PatK]

Building an own HTPC from scratch, when do I need a separate graphics card and when can I just use onboard graphics? So far I understand that there are the following reasons:

Your understanding isn't too far off base. If all you want is a HTPC with XBMC running 1080p video smoothly, and not likely to do much else. Then look at the minimums (other users messages re hardware in these forums are gold) but if you're looking for a well rounded desktop system, those 'other needs' dictate upgrades not necessary in a HTPC. Check out the Raspberry Pi thread... I'll have one in my sights.

1. Size. Obviously a mini-ITX case would not work for an additional card because it doesn't have enough space. While I really like these small cases, I also found a lot of nice micro- and macro-ATX cases. So this is not too important for me.

Nor I either... size is moot unless you want portability although very small would be nice if it could velcro on back of the TV panel!.. but then there's all that wiring (1080p on wifi is not here yet)

2. Gaming. I am actually not a big gamer. Actually I don't play games at all. But the reason could just be that I never bothered to buy a console and nice TV; computer was always a work machine. Still I enjoyed playing playstation, Xbox, wii, etc. when at friend's places. So the demand for playing games might come one I have a nice TV and HTPC. Still it would not be a top priority since I don't have much time anyways. But to what extent does gaming require a separate card? I like games like Pro Evolution Soccer, Mario Kart, Worms. Do these require an additional card?

Well this is the issue... Most great games these days rely on top graphic development coming from specialized gpu chips and frame rates accordingly... Indirectly HTPC benefit somewhat from these high speed gpu's and graphic card memories. The graphic card software has a lot more flexibility when it comes to driving modern flat panels, and the cards extra memory buffers help with frame rates and smoother flow of the video information. Given all that... it's impossible to see the difference from a $700 gfx card and $100 card, but most on board MB graphics still suck, except for the latest Intel MB's but I see quite a few threads in this forum complaining about i3 and i5 cpus and their onboard gfx, unless all the fixes have finally worked.

3. CPU. I understand a separate graphics card will let the CPU focus on other tasks rather than handling graphics on top. But is this critical for a normal running XBMC? I dont plan to do much processing, converting, etc. on that machine but only want to have a smoothly running HTPC. Any other tasks (converting/ripping, downloading, etc.) would probably run on a media server (NAS).

I would not say critical, but the strength of the rest of your system might determine responsiveness. I have an older (10 years old) system, which plays 1080p with a ATI 3460 gfx card.. (runs XP) but when I wanted to run XBMC, I got no hardware acceleration... So I had to buy a newer system if I wanted XBMC and yes I did want it. I looked on Toms Hardware a few years back for the BEST HTPC gfx card, and it looked like the 5450 at the time would do.... I ended up with a 5770 and have never looked back.

4. 1080p/BluRay. To what extent is an additional card required to get the best HD video quality?

This is were it gets complicated... You need to respect HTCP (copywrite protection) and it's handshaking all throughout the system including the graphic card or it will not play. Most users find that ripping the media and breaking digital locks to hard drive is the solution.. but depending on upcoming legislation, the country you're in yadyadda ripping and the accompanying software may be outlawed.

Of course this last bit takes a lot of CPU rendering power, mega memory requirements and massive storage solutions. So ending this conversation with a more is best statement isn't going to help you a lot.. So your homework is to read these forums, ask pertinent questions, and make informative decisions based on your needs and what others have recommend.

[bluray]

@jaochoo- the two HTPC's in my signature should playback everything in your list (post #2).

[>>X<<]

If your not going to play heavy games then you don't need a separate GPU that is unless you want to use GPU decoding and the integrated GPU doesn't play nice with DXVA

XBMC doesn't currently support multi threading from the CPU so using DXVA is probably a good idea

As far as decoding 1080p video using DXVA and rendering the XBMC GUI an external card isn't needed an iGPU will do just fine